#12 In 1998, the population of a colony is 10,000, and is decreasing exponentially at 1.5% per year. a) What will the population be after 5 years? b) In what year will there be half of the population left? #13 In 2003, the population of a city is 80,000 people, and is growing at a rate of 4% per year. a) What will the population be in 2015? b) In what year will the population be triple?